.paper,
.paper .origin {
    top: 50%;
    left: 50%;
    -webkit-transform: translate(-50%, -50%);
    -moz-transform: translate(-50%, -50%);
    -ms-transform: translate(-50%, -50%);
    transform: translate(-50%, -50%);
}

.paper {
    display: block;
    overflow: hidden;
    position: fixed;
}

.paper.A4 {
    width: 297mm;
    height: 210mm;
    box-shadow: 0 0 4px #3b3b3b;
    background-color: #fff;
}

.paper.A4 .origin {
    width: 9mm;
    height: 9mm;
    background-color: black;
}

.paper.A5 {
    width: 210mm;
    height: 148mm;
    box-shadow: 0 0 4px #3b3b3b;
    background-color: yellow;
}

.paper.A5 .origin {
    width: 17mm;
    height: 17mm;
    background-color: blue;
}

.paper .origin {
    display: block;
    overflow: hidden;
    position: relative;
    border-radius: 50%;
}

.panel_box {
    display: block;
    overflow: hidden;
    position: relative;
    font-size: 10px;
    max-width: 100em;
    margin: 0 auto;
}
